<template>
  <el-upload
    class="avatar-uploader"
    action=""
    :http-request="handleUpload"
    :before-upload="beforeAvatarUpload"
    :show-file-list="false"
  >
    <img v-if="imageUrl" :src="imageUrl" class="avatar" />
    <i v-else class="el-icon-plus avatar-uploader-icon"></i>
  </el-upload>
</template>

<script>
import Cloud from "leancloud-storage";
//将本地图片file对象，转换为base64编码
function getBase64(img, callback) {
  const reader = new FileReader();
  reader.addEventListener("load", () => callback(reader.result));
  reader.readAsDataURL(img);
}
export default {
  props: ["modelValue"],
  data() {
    return {
      imageUrl: "",
    };
  },
  methods: {
    handleUpload(info) {
      // console.log(info);
      getBase64(info.file, async (base64) => {
        // console.log(base64);
        let cloudFile = new Cloud.File("vue-admin-2303.png", { base64 }); //构建LeanCloud文件资源
        let res = await cloudFile.save(); //同步等待异步请求
        // console.log(res); //后端下发图片链接信息
        let { url } = res.attributes;
        this.imageUrl = url; //预览
        this.$emit("update", url);
      });
    },
    beforeAvatarUpload(file) {
      const isJPG = file.type === "image/jpeg" || file.type === "image/png";
      const isLt2M = file.size / 1024 / 1024 < 2;

      if (!isJPG) {
        this.$message.error("上传头像图片只能是 JPG 格式!");
      }
      if (!isLt2M) {
        this.$message.error("上传头像图片大小不能超过 2MB!");
      }
      return isJPG && isLt2M;
    },
  },
};
</script>

<style>
.avatar-uploader .el-upload {
  border: 1px dashed #d9d9d9;
  border-radius: 6px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}
.avatar-uploader .el-upload:hover {
  border-color: #409eff;
}
.avatar-uploader-icon {
  font-size: 28px;
  color: #8c939d;
  width: 178px;
  height: 178px;
  line-height: 178px;
  text-align: center;
}
.avatar {
  width: 178px;
  height: 178px;
  display: block;
}
</style>
